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Sierra 18-8205 Transom Seal Kit for MerCruiser Alpha 1 Stern Drives

Manufacturer

Sierra

<p>For nearly six decades, Sierra has established itself as one of the marine industry's most trusted names in aftermarket engine and drive parts. Founded as a specialized marine parts manufacturer, Sierra has grown into a comprehensive supplier of replacement components, instrumentation, and accessories for both recreational and commercial boating applications. Operating from their 300,000-square-foot distribution center in Litchfield, Illinois, Sierra serves boat owners and marine technicians worldwide with an extensive catalog of parts engineered specifically for the harsh saltwater environment.</p><h3>Marine Engine Excellence</h3><p>Sierra's reputation was built on delivering precision-engineered internal engine components and drive system parts that meet or exceed OEM specifications. Their <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> provide critical sealing solutions for inboard and outboard motors, while their <a href="/7570-sierra-engine-complete-assembly-15341">engine complete assemblies</a> offer comprehensive replacement options for major overhauls. Each component undergoes rigorous testing to ensure reliability in demanding marine conditions, from corrosion resistance to temperature cycling performance.</p><h3>Instrumentation and Monitoring Systems</h3><p>Accurate instrumentation is essential for boat operators to monitor engine health and prevent costly breakdowns on the water. Sierra's comprehensive line of <a href="/7570-sierra-gauges-200483">gauges</a> includes everything from fuel pressure and temperature indicators to voltmeters and trim gauges, all designed with marine-grade materials that withstand vibration, moisture, and UV exposure. Their <a href="/7570-sierra-tachometer-gauge-1488">tachometer gauges</a> deliver precise RPM readings critical for optimizing engine performance and fuel efficiency. Supporting these instruments, Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> ensure proper signal conditioning and accurate readings across various sensor types and engine configurations.</p><h3>Expanded Product Portfolio</h3><p>In 2022, Sierra significantly broadened its scope beyond traditional marine engine parts to encompass a wider range of boating accessories and even outdoor power equipment components. This strategic expansion brought established marine brands like Shields and Moeller under the Sierra umbrella, creating a one-stop resource for marine maintenance and replacement parts. The company now offers fuel systems, electrical components, battery charging solutions, and NMEA electronics alongside their traditional engine parts lineup.</p><h3>Quality Backed by Industry-Leading Warranties</h3><p>What sets Sierra apart in the crowded aftermarket marine parts market is their commitment to standing behind every component they manufacture. Their warranty coverage extends beyond simple part replacement—it includes shop labor, haul-out fees, towing charges, and related incidental costs should a warrantied part fail. This comprehensive protection reflects the company's confidence in their manufacturing processes and quality control standards. For boat owners facing repairs far from shore or mechanics working on customer vessels, this peace of mind is invaluable. Whether you're maintaining an outboard motor, rebuilding an inboard engine, or upgrading your boat's instrumentation, Sierra's decades of marine industry experience and commitment to quality make them a reliable choice for keeping your vessel running at peak performance.</p>

Part Number

18-8205
06/04/2036 9:27 AM
Sale Price

$242.89

In Stock (10+)

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Usually delivered within 2 days

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No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-8205 is a comprehensive transom seal kit designed for MerCruiser 1, R, MR, and Alpha 1 stern drives with exhaust tubes. This complete service kit includes everything needed to remove and reinstall a stern drive from the transom, making it ideal for routine maintenance and seal replacement on models from 1983 to 1990.

Key Features:

  • Complete transom service kit with all necessary gaskets, seals, and bellows
  • Features greasable gimbal bearing (18-2100) for extended service life
  • Includes U-joint bellows, shift cable bellows, and exhaust tube
  • Comes with both 5/8" and 3/4" ID water intake hoses
  • All required hose clamps, O-rings, and gaskets included
  • Designed to meet OEM specifications for reliable performance

Kit Contents:

  • Gimbal bearing (replaces Mercury 30-60794A4)
  • U-joint bellows (replaces 60932A4)
  • Exhaust tube (replaces 78458A1)
  • Water intake hoses (replaces 32-32461 and 32-41725-33)
  • Shift cable bellows (replaces 74639)
  • Drive shaft housing and bell housing gaskets
  • Multiple O-rings and hose clamps
  • Bellows clamps

This kit replaces Mercury Marine OEM part number 30-803098T1 and provides a cost-effective alternative while maintaining quality standards. Sierra is a trusted name in aftermarket marine parts, offering premium-quality components backed by comprehensive warranty coverage.

Products specifications

Application

Mercruiser: 30-803098T1

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